Active faceted nanoporous ruthenium for electrocatalytic hydrogen evolution

Abstract

Nanoporous ruthenium (np-Ru) comprising reaction active facets is synthesized from a ruthenium-cerium (Ru2Ce) alloy precursor. Spontaneous nanophase separation of Ru2Ce in an oxidative atmosphere results in a lamellar nanocomposite consisting of Ru metal and cerium oxide (CeO2). Selective leaching of the Ru-CeO2nanocomposite in sulfuric acid yields np-Ru with a high surface area of 48 m2g−1, predominantly surrounded by reaction active {101̄0} facets. Active-faceted np-Ru efficiently catalyzed the hydrogen evolution reaction (HER) in acidic media at an overpotential of +74 mVvs.the reversible hydrogen electrode, which is 20 mV lower than that for carbon-supported Ru (Ru/C) and rather close to +58 mV for state-of-the-art Pt/C. Np-Ru has great potential in broad applications such as hydrogen battery electrodes because of its low HER overpotential and scalable synthetic protocol.